For the production of finned heat exchanger pipes a number of different methods have been available, in which for instance the fin contact with the pipe is produced by a press fit, by welding or by brazing. A regular, predictable transfer of heat is however only possible if there is a welded or brazed joint between the fins and the metallic pipe. Welding on the fins to the metallic pipe however will mean that when the pipe is in operation it is subjected to high notch stresses. This prevents the use of such a pipe in certain applications where there is risk of fracture. The brazing on of the fins to the metallic pipe has proved to be the most apt method of attachment for heat exchanger pipes which are subject to high thermal and mechanical loads. The fins have to be held in the correct position during the brazing operation on the metallic pipe especially in the case of brazing in high vacuum, very elaborate holding devices have to be used which are not wetted by the spelter, as for instance ceramic and like materials. The welding of long finned heat exchanger pipes with fins placed close to each other has thus not been economically possible.